Direction selection condenser



March 11, 1952 J ROOT 2,588,577

DIRECTION SELECTION CONDENSER Filed Oct. 22. 1949 2 SHEETS-SHEET l March 11, 1952 J T 2,588,577

DIRECTION SELECTION CONDENSER Filed 001:. 22. 1949 2 SHEETSSHEET 2 \l I Ta. 1. El. Q0 4 IN ENTOR.

002 36 iz/WM 'ed in other circumstances. -=cation is a-continuationin part-f my priorap- 'plication Serial No. 72,700, filed January '25, 1 949,

directions around the receiver. ceivers conventionally requireantenna which are Patented Mar. 11, 1952 U N I T ED S TAT-ES 2,588,577 DIRECTION SELECTION CONDENSER John J.R.oot, New York, N. Y.

Application 0ct'ober'22, 194'9,'Serial No. 123,021

6 Claims.

This invention relates to direction selection condensers such as may be used in "television antenna systems although they maybe employ- The instant applinow abandoned.

in the above mentioned prior application-it 'was pointed out that television stations-are "generally dispersed in 'various directions relative to most television receivers. If a receiver is located in a central :districtgthe receivable transmitting stations may be disposed in virtuallyall Television --rehighly directional and which therefore require rotation or orientation in order to satisfactorily receive any particular transmission. It is'dif- :ficult to physically orient the antenna for each station that is tuned in, and in general, compromises are practiced by permanently orient- .ing the antenna in the general direction of the :most desired stations. Antennas are often in- .stalled Ldirectly within :or adjacent the :reciv'er cabinet so that physical orientation then Jaecomes practical. However, this :method ilimits the size of the antenna elements :and often involves undue production. :and :installation expenses.

.Inmy prior application, I describedtthe provision of crossed directional elements ewhich-were electrically connected to .a four-.partzrotary .condenser.

According to the present invention, the-mondenser is constructedsubstantially without-bolts :2, or any'iastening devices while the requiredcapacity and operating precision .is nevertheless maintained. The condenser further has a high efficiency in that some of itsplatesare-coated with a substance of low dielectric characteristies.

The condenser, as constructed herein, offers further manufacturing economies and installation conveniences, as willhereinafter be .made

clear.

. Referring to thedrawings:

Fig. 1 isa side .levational view of the com- ..plete rotary condenser of theinstant invention.

Fig. 2 is a front end view thereof in elevation.

Fig. 3 is-a rear end view thereof.

Fig. 4 is a side elevational view before'the stator plates are applied.

Fig. 5 is an enlarged cross-sectional view as taken along 'the lines '55 of Fig. '2.

Fig. '6 is .a developed view of a stator plate.

Fig. 7 is a developed view of the sprin termi11a1'. lug for the rotorplates.

the shaft.

plate 2 l.

"N T OFFICE Fig. 8 is a view taken substantially along the lines 8- 8 of Fig. 5.

Fig. 9 is a cross-sectional view taken substantially along the lines 99 of Fig. .5; and

Fig. 10 is a cross-sectional view :takensubstantially along the lines I-0-l.0 of 'Eig. The condenser comprises the four equispaced arcuate stator plates or segments l5, 1.6, l1 and H3 disposed edge to edge in a circle and insulated from each other. Such disposition-"Es maintained by the insulating disks 'I9-and 20E110 which the stator plates are physically connected. The device is employed by connecting ea'chvof 'the crossed directional antenna elements to 0pings 25 are generally round but have a flattened portion in order to conform 'tothecms's-sectiona1 shape of shaft-23.

Many methods may be employed in'assenibling the instant article but a 'pra'ctica'l mthod is as follows: Shaft 23 is first inserted through an opening 26 of depending arm -25-0f plate Q22 and an insulating spacer '2"! is then appliedover Thereafter, the shaft is passed through the depending arm opening of rot'or An insulating t1ibe'-28 is then-placed within the rotor plates and slipped overshaft Thereafter, shaft 2-3 -'is passed through the opp'oiste depending arm opening of "plate"'-22,

"another insulating spacer "29"isapfplied,- and depending arm opening of plate-2|. By these steps, "the rotor plates are correctly 'rrio'u'nted on the shaft in diametrically spaced relationship and are suitably insulated 'from-'--each-'ether. In order to maintain'such relationship, -a "pin 30 'is passed through tube 28 and shaft fl so as to prevent disassembly of the parts.

A pair of spring lugs 3| and 32 arenowdnsert'ed over shaft 23 on both 'sidesof therotor plate assembly. The spring lugs not onlyserve as fixed terminal "means for "the rotating-rotor "assembly but serve as stabilizers for "'its opera- "tion. They are formed of a 'resilientmetal and "may be silver-plated or the "liketofincrea'se com ductivity. As shown in Fig. 7, the spring lug is formed of a base section 33 and an arm 34 which is bent along line 35 so that the spring lug becomes essentiall L-shaped in form. Base section 33 is somewhat triangular in shape so as to form spring fingers 36. Such spring fingers are bent upwardly as illustrated in Figs. 4 and so as to provide the required spring action.

After application of the spring lugs on both ends of the rotor assembly, insulating spacers 31 and 38 are positioned at each end of the shaft. Thereafter, the insulating disks l9 and 20 are placed in position at the respective ends of the shaft.

The insulating disks I9 and 20 are formed with a plurality of openings 40 around the edges thereof. Each arm 34 of the spring lugs 3| and 32 is passed through one of said openings as illustrated in Figs. 2, 3 and 5. Disk 19 is provided with a central amiular, brass collar 42 which fits over the shaft 23. In the same manner, disk 20 is provided with a brass collar 43 having a threaded end 44 which may serve to receive a nut as when the device is to be secured to a cabinet wall.

In order to maintain the assembly of the disks and other components as heretofore described,

-the four stator plates I5, [6, I1 and I8 are now applied over the rotor plates and so as to jointly grasp and secure the disks. Referring to Fig. 6, which is a developed view of a stator plate, it will be observed that the plate is out along line 45 so as to provide a projection or lug 46.- The other end is out along line 41 so as to provide a projection or lug 48 and an electrical connection lug 49. The stator plate is then rendered concave-convex in form as by any suitable die. Projections 46 and 48 are bent inwardly so that such lugs are made available for connection to the disks while the lug 49 is employed for electrical connection to the antenna elements. In .order to connect the stator plates in position, projection 46 is inserted in a bottom opening 40 of disk l9 as illustrated in Fig, 3 While the top projection 48 is snapped into an opening 40 of disk 20. All four stator plates are thus applied, the end result being the formation of the complete rotary condenser as illustrated in Figs. 1 and 5. It will be observed from the foregoing that substantially no screws or bolts were required in assembling the article, such assembly being effected by the stator plates and being rendered stable and precise through the spring action of the lugs 3| and 32.

In order to improve the operating characteristics of the condenser over a wide range of frequencies, I determined that the dielectric factor between the condenser plates should be decreased in order to eliminate sharp or peak tuning at particular points so as to widen the response curve. This expedient is very useful in that the condenser is intended to operate over a wide band of frequencies, and sharp tuning at any particular points should be avoided. To this end, I have applied a thin coating of graphite 55 to the periphery of the rotor plates. As a result of such coating, stability and uniformity of operation over the wide band of frequencies required is accomplished.

Briefly, the rotary condenser is employed as follows:

A pair of dipoles are disposed in crossed relationship so as to form four inner terminal ends approximately 90 degrees apart. Each terminal end is then connected to a respective lug 49 of each stator plate. Accordingly, each stator plate represents one dipole section. Connections are then made from arms 34 to the input terminals of the'television receiver. It will be recognized therefore that rotation of shaft 23 will rotate the rotor plates 2| and 22 so as to capacitatively derive antenna voltages from any particular quadrant of the composite directional antenna elements. Thus, the rotation of shaft 23 is equivalent to physically rotating a directional antenna.

The rotary condenser of the instant invention may be employed with an outside antenna or with one that is mounted within or adjacent to the television receiver cabinet. Inasmuch as physical rotation of the antenna is eliminated, it may be disposed in ordinarily inaccessible places and may be made of larger elements than would be practical or possible, if it was to be physically rotated.

What is claimed is:

1. A rotary condenser comprising a plurality of arcuate stator plates edge-to-edge disposed in a circle and insulated from each other, a pair of insulating disks at the respective ends of said stator plates, said disks being formed with openings therethrough, integral snap lugs formed on each stator plate and received into said disk openings so as to effect a physical connection between said stator plates and disks for maintaining said stator plates in their circular disposition, a rotatab-e shaft, and a pair of rotor plates mounted on said shaft so as to be adjacent and rotatable relative to said stator plates for condenser action with selectable ones of said stator plates.

2. A rotary condenser comprising a plurality of arcuate stator plates edge-to-edge disposed in a circle and insulated from each other, a pair of insulating disks at the respective ends of said stator plates, said disks being formed with openings therethrough, integral snap lugs formed on each stator plate and received into said disk openings so as to effect a physical connection between said stator plates and disks for maintaining said stator plates in their circular disposition, a pair of rotor plates mounted within said stator plates for condenser action with selectable ones of said stator plates, a shaft extending through said disks and upon which said rotor plates are mounted, and a pair of spring lugs mounted on such shaft, each spring lug having a spring portion thereof disposed between one of said rotor plates and one of said disks so as to bear against said rotor plate and disk respectively with a spring force, each of said spring lugs further including a projection extending through the disk against which it bears, said projection serving as an electrical terminal for the rotor plate against which the spring lug bears.

3. A rotary condenser comprising a plurality of arcuate stator plates edge-to-edge disposed in a circle and insulated from each other, a pair of insulating disks at the respective ends of said stator plates, said disks being formed with openings therethrough, integral snap lugs formed on each stator plate and received into said disk openings so as to effect a physical connection between said stator plates and disks for maintaining said stator plates in their circular disposition, a pair of rotor plates mounted within said stator plates for condenser action with selectable ones of said stator plates, a shaft extending through said disks and upon which said rotor plates are mounted, and a pair of spring lugs mounted on such shaft, each spring lug having a spring portion thereof disposed between one of said rotor plates and one of said disks so as to bear against said rotor plate and disk respectively with a spring force, each of said spring lugs further including a projection extending through the disk against which it bears, said projection serving as an electrical terminal for the rotor plate against which the spring lug bears, each of said rotor plates having an outer coating of graphite.

4. A rotary condenser comprising a plurality of arcuate stator plates edge-to-edge disposed and insulated from each other, a pair of insulating disks each connected at the respective ends of the stator plates and supporting said plates, a pair of rotor plates mounted for condenser action with selectable ones of said stator plates and spring lugs efiecting contact with said rotor plates and extending through said disks so as to serve as terminals for said rotor plates, each of said spring lugs comprising a base having a spring member thereon, one terminal of said spring member abutting against one of said rotor plates and the other terminal abutting against one of said disks so as to eifect a secure mechanical assembly between the disks and the stator plates while providing an electrical connection to the rotor plates.

5. A rotary condenser according to claim 4 and wherein each of said disks is formed with a plurality of openings therethrough, and an offset integral member on each of said stator plates entering into, so as to be engaged by, said openings in said disks.

6. A rotary condenser comprising a plurality of arcuate stator plates edge-to-edge disposed and insulated from each other, a pair of insulating disks connected at the respective ends of the stator plates, a pair of rotor plates mounted for condenser action with selectable ones of said stator plates and spring lugs effecting contact with said rotor plates and extending through said disks so as to serve as terminals for said rotor plates, each of said rotor plates having end depending arms formed with an opening therethrough, and a shaft extending through each of said depending arm openings and through said disks, each of said disks being formed with a plurality of edge openings therethrough and an ofiset integral member on each of said stator plates snapped into said openings of said disks.

JOHN J. ROOT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,297,313 Bellini Mar. 18, 1919 1,506,781 Shrader Sept. 2, 1924 2,290,875 Greibach July 28, 1942 2,483,047 Herrick Sept. 27, 1949 

